Add option for selecting disk type (SSD/NVME)

[casper-hansen]

Is your feature request related to a problem? Please describe.
The web interface for RunPod allows the user to select the Disk Type of the pod. I would like to have this available in the SDK since this can make a big difference in the speed of quantizing big models. NVME significantly speeds things up.

Describe the solution you'd like
Implement a new argument for runpod.create_pod that is called disk_type which defaults to SSD like in the UI, but which also accepts NVME.

Describe alternatives you've considered
There are no official alternatives if you want to programmatically launch a pod with NVME. The only alternative is reverse engineering the GraphQL calls and making them yourselves.